Wafer processing tools for wet platforms, e.g., chemical mechanical planarization (CMP), are based on the “dry-in/dry-out” principle although the majority of the processes are wet processes. Accordingly, the tools are designed to deliver dry wafers to a front opening unified pod (FOUP) from the last process chamber. However, a malfunction of the tool or a hardware failure may cause wet and/or contaminated wafers, e.g., with wet backsides, to be transferred to the FOUP. Wet, or otherwise contaminated, wafers in the FOUP can contaminate other wafers in the FOUP as well as wafer handling equipment in any subsequent processes. Current processes fail to detect this error.
A need therefore exists for methodology and apparatus enabling the detection of moisture and/or electrically conductive remains on wafers prior to delivery to the FOUP.